The IP3 setup I showed is for any DUT. If a mixer is the DUT, then an LO would obviously be required for the mixer, but this is really part of the DUT. It's worth experimenting with different LO drive levels for the mixer though.
Quote:
I am making a comparison between HP8566B and SSA3021X Plus:
HP8566B:
TOI > +7dbm (5M-5.8G) . DANL < -134dbm (0 atten, 10Hz RBW, 1M-20Ghz) . phase noise -90dbc/Hz at 10KHz offset.
SSA3021X +:
TOP: +10 to + 18dbm. DANL, -161dbm/hz (0 atten at RBW 1 Hz). Phase noise, -98dbc/Hz at 10KHz
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I've got an old HP8566B here and the TOI for the 8655B mixer is typically +8dBm to +10dBm at VHF with 0dB attenuation. At VHF test frequencies, the DANL is typically -140dBm with 0dB attenuation and 10Hz RBW. This implies that the noise figure is about 24dB at VHF.
The HP8566B doesn't have great phase noise, partly because the IF is at about 3.6GHz on the lowest band. However, it is typically going to be about the same as the Siglent when measured at 10kHz offset at about -98dBc/Hz at VHF test frequencies. The HP 8566B phase noise will be much lower than the Siglent when measured at 100kHz offset. Probably 20dB lower because it uses a YIG oscillator. My 8566B is really an HP8566A that has had the factory conversion to a B. I think the later B versions had improved phase noise but not by much.
If I look at the datasheet for the Siglent SSA3021X, the DANL is -129dBm with a 10Hz RBW and 0dB attenuation. This implies that the noise figure is about 35dB. The TOI is +10dBm with the same setup conditions. The Siglent has a preamp that can improve the noise figure, but it will also degrade the TOI quite a lot when selected. It does look like the 8566B generally has a higher dynamic range than the Siglent.
Newer lab analysers are much better than the HP 8566B though. My Agilent E4440A analyser is about 15 years old and has -117dBc/Hz phase noise at 10kHz offset and the DANL is about -145dBm with 0dB attenuation at 10Hz RBW (no preamp selected). This implies that the noise figure is about 19dB. The mixer TOI is about 19dBm with 0dB attenuation. The modern PXA and UXA signal analysers are even better.